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I think you are in luck and your tranny has not given out. DTC 1-2-4 is "Short-circuit to ground in mode selector circuit". Basically, the Winter/Economy/Sport selector on you center console is a fault. There are three possibilities, 1) There is a short circuit in the signal wiring. 2)The W button has been depressed for more than 30 seconds (which causes a fault) or 3) defective mode selector. Believe it or not, when this fault is stored the transmission will only operate in driving mode E regardless of the position selected on the gear selector! Have the driving mode selector checked out for proper resistance, signal or short circuit.